Recent discoveries of transiting giant exoplanets (Rp \u2273 8 R⊕) around M dwarfs present an opportunity to investigate their atmospheric compositions and explore how such massive planets form around low-mass stars contrary to the prediction from formation models. We present the first transmission spectra of TOI-5205b, a short-period (P = 1.63 days) Jupiter-like planet (Mp = 1.08 MJ and Rp = 0.94 RJ) orbiting an M4 dwarf (M\u22c6 = 0.392 M\u2299, R\u22c6 = 0.394 R\u2299). We obtained three transits using the PRISM mode of the JWST Near Infrared Spectrograph spanning 0.6–5.3 μm. The data reveal significant stellar contamination that is evident in the light curves as spot-crossing events and in the transmission spectra as a larger transit depth at bluer wavelengths. Atmospheric retrievals demonstrate that stellar contamination from unocculted starspots and faculae is the dominant component of the transmission spectrum at wavelengths λ \u2272 3.0 μm, reducing the sensitivity to the presence of clouds or hazes in our models and preventing detection of H2O. The wavelength coverage enabled a robust detection of CH4 and H2S, which have detectable molecular features between 3.0 and 5.0 μm. For both clear or cloudy atmospheres, Bayesian retrievals consistently favored an atmosphere with subsolar metallicity (3σ upper limit of log [C/O] \u2273 0.09), and supersolar C/O ratio (3σ lower limit of log [M/H] \u2272 −1.24), although this may partly be driven by the nondetection of water due to stellar contamination. Planetary interior models predict a bulk metallicity of 10%–20%, which is larger than the atmospheric metallicity and suggests that the interior of TOI-5205b is decoupled from its atmosphere.
", "doi": "10.3847/1538-3881/ae4976", "issn": "0004-6256", "publisher": "American Astronomical Society", "publication": "Astronomical Journal", "publication_date": "2026-04", "series_number": "4", "volume": "171", "issue": "4", "pages": "260" }, { "id": "authors:2b96g-3gp28", "collection": "authors", "collection_id": "2b96g-3gp28", "cite_using_url": "https://authors.library.caltech.edu/records/2b96g-3gp28", "type": "article", "title": "Spectroscopic characterization of LOFAR radio-emitting M dwarfs", "author": [ { "family_name": "Koo", "given_name": "E.", "orcid": "0009-0007-0740-0954" }, { "family_name": "Stefansson", "given_name": "G." }, { "family_name": "Kavanagh", "given_name": "R. D.", "orcid": "0000-0002-1486-7188" }, { "family_name": "Delamer", "given_name": "M.", "orcid": "0000-0003-1439-2781" }, { "family_name": "Mahadevan", "given_name": "S.", "orcid": "0000-0001-9596-7983" }, { "family_name": "Callingham", "given_name": "J. R.", "orcid": "0000-0002-7167-1819" }, { "family_name": "Vedantham", "given_name": "H.", "orcid": "0000-0002-0872-181X" }, { "family_name": "Robertson", "given_name": "P.", "orcid": "0000-0003-0149-9678" }, { "family_name": "Bruijne", "given_name": "D." }, { "family_name": "Bender", "given_name": "C. F.", "orcid": "0000-0003-4384-7220" }, { "family_name": "Ca\u00f1as", "given_name": "C. I.", "orcid": "0000-0003-4835-0619" }, { "family_name": "Diddams", "given_name": "S.", "orcid": "0000-0002-2144-0764" }, { "family_name": "Espinoza-Retamal", "given_name": "J. I.", "orcid": "0000-0001-9480-8526" }, { "family_name": "Fernandes", "given_name": "R. B.", "orcid": "0000-0002-3853-7327" }, { "family_name": "Halverson", "given_name": "S.", "orcid": "0000-0003-1312-9391", "clpid": "Halverson-Samuel" }, { "family_name": "Kanodia", "given_name": "S.", "orcid": "0000-0001-8401-4300" }, { "family_name": "Krolikowski", "given_name": "D.", "orcid": "0000-0001-9626-0613" }, { "family_name": "Lin", "given_name": "A. S. J.", "orcid": "0000-0002-9082-6337", "clpid": "Lin-Andrea-S-J" }, { "family_name": "Pope", "given_name": "B. J. S.", "orcid": "0000-0003-2595-9114" }, { "family_name": "Roy", "given_name": "A.", "orcid": "0000-0001-8127-5775" }, { "family_name": "Schwab", "given_name": "C.", "orcid": "0000-0002-4046-987X" }, { "family_name": "Terrien", "given_name": "R.", "orcid": "0000-0002-4788-8858" }, { "family_name": "Wright", "given_name": "J. T.", "orcid": "0000-0001-6160-5888" } ], "abstract": "Recent observations with the LOw Frequency ARray (LOFAR) have revealed 19 nearby M dwarfs showing bright circularly polarized radio emission. One of the possible sources of such emission is through magnetic star-planet interactions (MSPIs) with unseen close-in planets. We present the initial results from a spectroscopic survey with the Habitable-zone Planet Finder (HPF) and NEID spectrographs designed to characterize this sample and further investigate the origin of the radio emission. We provide four new insights into the sample. I) We uniformly characterized the stellar properties, constraining their effective temperatures (Teff), surface gravities (log g), metallicities ([Fe/H]), projected rotational velocities (v sin i\u22c6), rotation periods (Prot), stellar radii (R\u22c6), and stellar inclinations (i\u22c6) where possible. Further, from a homogeneous analysis of the HPF spectra, we inferred their chromospheric activity and spectroscopic multiplicity states. From this, we identified GJ 625, GJ 1151, and LHS 2395 as single, quiescent stars amenable to precise radial velocity follow-up, making them strong MSPI candidates. II) We show that the distribution of stellar inclinations are compatible with an isotropic distribution, providing no evidence for a preference to pole-on configurations. III) We refined the radial velocity solution for GJ 625 b, the only currently known close-in planet in the sample, reducing the uncertainty in its orbital period by a factor of three, to facilitate future phase-dependent radio analysis. IV) Finally, we identified GJ 3861 as a spectroscopic binary with an orbital period of P = 14.841181−0.00010+0.00011 d and with a mass ratio of q = 0.7663−0.0018+0.0020, making it the only confirmed binary with a relatively short orbit in the sample, where we surmise the radio emission is likely related to magnetospheric interactions between the two stars. These results advance our understanding of radio-emitting M dwarfs and establish an observational foundation for identifying MSPIs.
", "doi": "10.1051/0004-6361/202556483", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy & Astrophysics", "publication_date": "2026-02", "volume": "706", "pages": "A98" }, { "id": "authors:55s7k-wsx03", "collection": "authors", "collection_id": "55s7k-wsx03", "cite_using_url": "https://authors.library.caltech.edu/records/55s7k-wsx03", "type": "article", "title": "Searching for GEMS: TOI-5349 b is a Saturn-like Planet Orbiting a Metal-rich Early M Dwarf", "author": [ { "family_name": "Sandoval", "given_name": "Angeli", "orcid": "0000-0003-1133-1027" }, { "family_name": "Ca\u00f1as", "given_name": "Caleb I.", "orcid": "0000-0003-4835-0619" }, { "family_name": "Kanodia", "given_name": "Shubham", "orcid": "0000-0001-8401-4300" }, { "family_name": "Col\u00f3n", "given_name": "Knicole D.", "orcid": "0000-0001-8020-7121" }, { "family_name": "Monson", "given_name": "Andrew", "orcid": "0000-0002-0048-2586" }, { "family_name": "Larsen", "given_name": "Alexander", "orcid": "0000-0002-2401-8411" }, { "family_name": "Swaby", "given_name": "Tera N.", "orcid": "0000-0002-5817-202X" }, { "family_name": "Kobulnicky", "given_name": "Henry A.", "orcid": "0000-0002-4475-4176" }, { "family_name": "Choi", "given_name": "Philip I." }, { "family_name": "Santomenna", "given_name": "Sage", "orcid": "0000-0002-8623-8268" }, { "family_name": "Qin", "given_name": "Pei" }, { "family_name": "Rodruck", "given_name": "Michael", "orcid": "0009-0009-4977-1010" }, { "family_name": "Cochran", "given_name": "William D.", "orcid": "0000-0001-9662-3496" }, { "family_name": "Brown", "given_name": "Nina", "orcid": "0009-0003-1142-292X" }, { "family_name": "Brady", "given_name": "Madison", "orcid": "0000-0003-2404-2427" }, { "family_name": "Seifahrt", "given_name": "Andreas", "orcid": "0000-0003-4526-3747" }, { "family_name": "Gupta", "given_name": "Arvind F.", "orcid": "0000-0002-5463-9980" }, { "family_name": "Higuera", "given_name": "Jesus", "orcid": "0000-0002-3985-8528" }, { "family_name": "Everett", "given_name": "Mark E.", "orcid": "0000-0002-0885-7215" }, { "family_name": "Barksdale", "given_name": "Zuri", "orcid": "0009-0000-2465-3119" }, { "family_name": "Basant", "given_name": "Ritvik", "orcid": "0000-0003-4508-2436" }, { "family_name": "Bean", "given_name": "Jacob L.", "orcid": "0000-0003-4733-6532" }, { "family_name": "Diddams", "given_name": "Scott A.", "orcid": "0000-0002-2144-0764" }, { "family_name": "Caloca", "given_name": "Giannina Guzm\u00e1n", "orcid": "0000-0001-6340-8220" }, { "family_name": "Halverson", "given_name": "Samuel", "orcid": "0000-0003-1312-9391", "clpid": "Halverson-Samuel" }, { "family_name": "Libby-Roberts", "given_name": "Jessica", "orcid": "0000-0002-2990-7613" }, { "family_name": "Lin", "given_name": "Andrea S. J.", "orcid": "0000-0002-9082-6337", "clpid": "Lin-Andrea-S-J" }, { "family_name": "Luque", "given_name": "Rafael", "orcid": "0000-0002-4671-2957" }, { "family_name": "Roy", "given_name": "Arpita", "orcid": "0000-0001-8127-5775" }, { "family_name": "Stef\u00e1nsson", "given_name": "Gu\u0111mundur", "orcid": "0000-0001-7409-5688" } ], "abstract": "We report the confirmation and analysis of TOI-5349 b, a transiting, warm, Saturn-like planet orbiting an early M dwarf with a period of ∼3.3 days, which we confirmed as part of the Searching for GEMS survey. TOI-5349 b was initially identified in photometry from NASA’s Transiting Exoplanet Survey Satellite mission and subsequently confirmed using high-precision radial velocity (RV) measurements from the Habitable-zone Planet Finder and MAROON-X spectrographs, and from ground-based transit observations obtained using the 0.6 m telescope at Red Buttes Observatory and the 1.0 m telescope at the Table Mountain Facility of Pomona College. From a joint fit of the RV and photometric data, we determine the planet’s mass and radius to be 0.40 ± 0.02 MJ (127.4_(−5.7)^(+5.9) M⊕) and 0.91 ± 0.02 RJ (10.2 ± 0.3 R⊕), respectively, resulting in a bulk density of ρp = 0.66 ± 0.06 g cm−3 (∼0.96 the density of Saturn). We determine that the host star is a metal-rich M1-type dwarf with a mass and radius of 0.61 ± 0.02 M\u2299 and 0.58 ± 0.01 R\u2299, and an effective temperature of Teff = 3751 ± 59 K. Our analysis highlights an emerging pattern, exemplified by TOI-5349, in which transiting Giant Exoplanets around M dwarf Stars (GEMS) often have Saturn-like masses and densities and orbit metal-rich stars. With the growing sample of GEMS planets, comparative studies of short-period gas giants orbiting M dwarfs and Sun-like stars are needed to investigate how metallicity and disk conditions shape the formation and properties of these planets.
", "doi": "10.3847/1538-3881/ae16a2", "issn": "0004-6256", "publisher": "American Astronomical Society", "publication": "Astronomical Journal", "publication_date": "2026-01", "series_number": "1", "volume": "171", "issue": "1", "pages": "43" }, { "id": "authors:scabg-tav58", "collection": "authors", "collection_id": "scabg-tav58", "cite_using_url": "https://authors.library.caltech.edu/records/scabg-tav58", "type": "article", "title": "Discovery of a Nearby Habitable Zone Super-Earth Candidate Amenable to Direct Imaging", "author": [ { "family_name": "Beard", "given_name": "Corey", "orcid": "0000-0001-7708-2364" }, { "family_name": "Robertson", "given_name": "Paul", "orcid": "0000-0003-0149-9678" }, { "family_name": "Lubin", "given_name": "Jack", "orcid": "0000-0001-8342-7736" }, { "family_name": "Ford", "given_name": "Eric B.", "orcid": "0000-0001-6545-639X" }, { "family_name": "Mahadevan", "given_name": "Suvrath", "orcid": "0000-0001-9596-7983" }, { "family_name": "Stefansson", "given_name": "Gudmundur", "orcid": "0000-0001-7409-5688" }, { "family_name": "Wright", "given_name": "Jason T.", "orcid": "0000-0001-6160-5888" }, { "family_name": "Wolf", "given_name": "Eric", "orcid": "0000-0002-7188-1648" }, { "family_name": "Kofman", "given_name": "Vincent", "orcid": "0000-0002-5060-1993" }, { "family_name": "Venkatesan", "given_name": "Vidya", "orcid": "0000-0002-5638-4344" }, { "family_name": "Kopparapu", "given_name": "Ravi", "orcid": "0000-0002-5893-2471" }, { "family_name": "Arendtsz", "given_name": "Roan", "orcid": "0009-0001-6669-264X" }, { "family_name": "Holcomb", "given_name": "Rae", "orcid": "0000-0002-5034-9476" }, { "family_name": "Martinez", "given_name": "Raquel A.", "orcid": "0000-0001-6301-896X" }, { "family_name": "Sallum", "given_name": "Stephanie", "orcid": "0000-0001-6871-6775" }, { "family_name": "Luhn", "given_name": "Jacob K.", "orcid": "0000-0002-4927-9925", "clpid": "Luhn-Jacob-K" }, { "family_name": "Bender", "given_name": "Chad F.", "orcid": "0000-0003-4384-7220" }, { "family_name": "Blake", "given_name": "Cullen H.", "orcid": "0000-0002-6096-1749" }, { "family_name": "Cochran", "given_name": "William D.", "orcid": "0000-0001-9662-3496" }, { "family_name": "Delamer", "given_name": "Megan", "orcid": "0000-0003-1439-2781" }, { "family_name": "Diddams", "given_name": "Scott A.", "orcid": "0000-0002-2144-0764" }, { "family_name": "Endl", "given_name": "Michael", "orcid": "0000-0002-7714-6310" }, { "family_name": "Halverson", "given_name": "Samuel", "orcid": "0000-0003-1312-9391", "clpid": "Halverson-Samuel" }, { "family_name": "Kanodia", "given_name": "Shubham", "orcid": "0000-0001-8401-4300" }, { "family_name": "Krolikowski", "given_name": "Daniel M.", "orcid": "0000-0001-9626-0613" }, { "family_name": "Lin", "given_name": "Andrea S. J.", "orcid": "0000-0002-9082-6337", "clpid": "Lin-Andrea-S-J" }, { "family_name": "Logsdon", "given_name": "Sarah E.", "orcid": "0000-0002-9632-9382" }, { "family_name": "McElwain", "given_name": "Michael W.", "orcid": "0000-0003-0241-8956" }, { "family_name": "Monson", "given_name": "Andrew", "orcid": "0000-0002-0048-2586" }, { "family_name": "Ninan", "given_name": "Joe P.", "orcid": "0000-0001-8720-5612" }, { "family_name": "Rajagopal", "given_name": "Jayadev", "orcid": "0000-0002-2488-7123" }, { "family_name": "Roy", "given_name": "Arpita", "orcid": "0000-0001-8127-5775" }, { "family_name": "Schwab", "given_name": "Christian", "orcid": "0000-0002-4046-987X" }, { "family_name": "Terrien", "given_name": "Ryan C.", "orcid": "0000-0002-4788-8858" } ], "abstract": "We present the discovery of GJ 251 c, a candidate super-Earth orbiting in the habitable zone (HZ) of its M dwarf host star. Using high-precision Habitable-zone Planet Finder and NEID RVs, in conjunction with archival RVs from the Keck I High Resolution Echelle Spectrometer, the Calar Alto High-resolution Search for M dwarfs with Exoearths with Near-infrared and optical Echelle Spectrograph, and the Spectropolarimétre Infrarouge, we improve the measured parameters of the known planet, GJ 251 b (Pb = 14.2370 days; m sin(i) = 3.85_(−0.33)^(+0.35) M⊕), and we significantly constrain the minimum mass of GJ 251 c, placing it in a plausibly terrestrial regime (Pc = 53.647 ± 0.044 days; m sin ic = 3.84 ± 0.75 M⊕). Using activity mitigation techniques that leverage chromatic information content, we perform a color-dependent analysis of the system and a detailed comparison of more than 50 models that describe the nature of the planets and stellar activity in the system. Due to GJ 251's proximity to Earth (5.5 pc), next generation, 30 meter class telescopes will likely be able to image terrestrial planets in GJ 251's HZ. In fact, GJ 251 c is currently the best candidate for terrestrial, HZ planet imaging in the northern sky.
", "doi": "10.3847/1538-3881/ae0e20", "issn": "0004-6256", "publisher": "American Astronomical Society", "publication": "Astronomical Journal", "publication_date": "2025-11", "series_number": "5", "volume": "170", "issue": "5", "pages": "279" }, { "id": "authors:9ytky-x3k24", "collection": "authors", "collection_id": "9ytky-x3k24", "cite_using_url": "https://authors.library.caltech.edu/records/9ytky-x3k24", "type": "article", "title": "The NEID Earth Twin Survey. III. Survey Performance after Three Years on Sky", "author": [ { "family_name": "Gupta", "given_name": "Arvind F.", "orcid": "0000-0002-5463-9980" }, { "family_name": "Fitzmaurice", "given_name": "Evan", "orcid": "0000-0003-0199-9699" }, { "family_name": "Mahadevan", "given_name": "Suvrath", "orcid": "0000-0001-9596-7983" }, { "family_name": "Robertson", "given_name": "Paul", "orcid": "0000-0003-0149-9678" }, { "family_name": "Luhn", "given_name": "Jacob K.", "orcid": "0000-0002-4927-9925", "clpid": "Luhn-Jacob-K" }, { "family_name": "Wright", "given_name": "Jason T.", "orcid": "0000-0001-6160-5888" }, { "family_name": "Logsdon", "given_name": "Sarah E.", "orcid": "0000-0002-9632-9382" }, { "family_name": "Krolikowski", "given_name": "Daniel M.", "orcid": "0000-0001-9626-0613" }, { "family_name": "Paredes", "given_name": "Leonardo A.", "orcid": "0000-0003-1324-0495" }, { "family_name": "Bender", "given_name": "Chad F.", "orcid": "0000-0003-4384-7220" }, { "family_name": "Giovinazzi", "given_name": "Mark R.", "orcid": "0000-0002-0078-5288" }, { "family_name": "Lin", "given_name": "Andrea S.J.", "orcid": "0000-0002-9082-6337", "clpid": "Lin-Andrea-S-J" }, { "family_name": "Blake", "given_name": "Cullen H.", "orcid": "0000-0002-6096-1749" }, { "family_name": "Ca\u00f1as", "given_name": "Caleb I.", "orcid": "0000-0003-4835-0619" }, { "family_name": "Ford", "given_name": "Eric B.", "orcid": "0000-0001-6545-639X" }, { "family_name": "Halverson", "given_name": "Samuel", "orcid": "0000-0003-1312-9391", "clpid": "Halverson-Samuel" }, { "family_name": "Kanodia", "given_name": "Shubham", "orcid": "0000-0001-8401-4300" }, { "family_name": "McElwain", "given_name": "Michael W.", "orcid": "0000-0003-0241-8956" }, { "family_name": "Monson", "given_name": "Andrew", "orcid": "0000-0002-0048-2586" }, { "family_name": "Ninan", "given_name": "Joe P.", "orcid": "0000-0001-8720-5612" }, { "family_name": "Rajagopal", "given_name": "Jayadev", "orcid": "0000-0002-2488-7123" }, { "family_name": "Roy", "given_name": "Arpita", "orcid": "0000-0001-8127-5775" }, { "family_name": "Schwab", "given_name": "Christian", "orcid": "0000-0002-4046-987X" }, { "family_name": "Stef\u00e1nsson", "given_name": "Gu\u00f0mundur", "orcid": "0000-0001-7409-5688" }, { "family_name": "Terrien", "given_name": "Ryan C.", "orcid": "0000-0002-4788-8858" } ], "abstract": "The NEID Earth Twin Survey (NETS) has been delivering a rich set of precise radial velocity (RV) measurements for 41 bright, nearby main-sequence stars. Here, we describe the status of the survey after 3 yr on sky, and we present the full set of RV measurements and accompanying stellar activity indicators. We discuss intermediate survey diagnostics, including calibration of the known RV zero-point offset introduced following the Contreras fire in 2022 and the identification of an undiagnosed and previously unknown zero-point offset in 2021. An analysis of our data set using RVSearch demonstrates that for these target stars, NEID is independently sensitive to nearly all known planets with periods shorter than the NETS observing baseline. We also highlight a number of newly detected RV signals, which present exciting opportunities for future investigations.
", "doi": "10.3847/1538-3881/ae0339", "issn": "0004-6256", "publisher": "American Astronomical Society", "publication": "Astronomical Journal", "publication_date": "2025-11", "series_number": "5", "volume": "170", "issue": "5", "pages": "264" }, { "id": "authors:fwnpy-3kd23", "collection": "authors", "collection_id": "fwnpy-3kd23", "cite_using_url": "https://authors.library.caltech.edu/records/fwnpy-3kd23", "type": "article", "title": "Searching for GEMS: Confirmation of TOI-5573 b, a Cool, Saturn-like Planet Orbiting an M Dwarf", "author": [ { "family_name": "Fernandes", "given_name": "Rachel B.", "orcid": "0000-0002-3853-7327" }, { "family_name": "Kanodia", "given_name": "Shubham", "orcid": "0000-0001-8401-4300" }, { "family_name": "Delamer", "given_name": "Megan", "orcid": "0000-0003-1439-2781" }, { "family_name": "Hotnisky", "given_name": "Andrew", "orcid": "0009-0000-1825-4306" }, { "family_name": "Han", "given_name": "Te", "orcid": "0000-0002-7127-7643" }, { "family_name": "Ca\u00f1as", "given_name": "Caleb I.", "orcid": "0000-0003-4835-0619" }, { "family_name": "Libby-Roberts", "given_name": "Jessica", "orcid": "0000-0002-2990-7613" }, { "family_name": "Reji", "given_name": "Varghese", "orcid": "0009-0006-7298-619X" }, { "family_name": "Gupta", "given_name": "Arvind F.", "orcid": "0000-0002-5463-9980" }, { "family_name": "Alvarado-Montes", "given_name": "Jaime A.", "orcid": "0000-0003-0353-9741" }, { "family_name": "Bender", "given_name": "Chad F.", "orcid": "0000-0003-4384-7220" }, { "family_name": "Blake", "given_name": "Cullen H.", "orcid": "0000-0002-6096-1749" }, { "family_name": "Cochran", "given_name": "William D.", "orcid": "0000-0001-9662-3496" }, { "family_name": "de Beurs", "given_name": "Zo\u00eb L.", "orcid": "0000-0002-7564-6047" }, { "family_name": "Diddams", "given_name": "Scott A.", "orcid": "0000-0002-2144-0764" }, { "family_name": "Dong", "given_name": "Jiayin", "orcid": "0000-0002-3610-6953" }, { "family_name": "Everett", "given_name": "Mark E.", "orcid": "0000-0002-0885-7215" }, { "family_name": "Ford", "given_name": "Eric B.", "orcid": "0000-0001-6545-639X" }, { "family_name": "Halverson", "given_name": "Samuel", "orcid": "0000-0003-1312-9391", "clpid": "Halverson-Samuel" }, { "family_name": "Higuera", "given_name": "Jesus", "orcid": "0000-0002-3985-8528" }, { "family_name": "Kobulnicky", "given_name": "Henry A.", "orcid": "0000-0002-4475-4176" }, { "family_name": "Krolikowski", "given_name": "Daniel M.", "orcid": "0000-0001-9626-0613" }, { "family_name": "Larsen", "given_name": "Alexander", "orcid": "0000-0002-2401-8411" }, { "family_name": "Lin", "given_name": "Andrea S.J.", "orcid": "0000-0002-9082-6337", "clpid": "Lin-Andrea-S-J" }, { "family_name": "Mahadevan", "given_name": "Suvrath", "orcid": "0000-0001-9596-7983" }, { "family_name": "McElwain", "given_name": "Michael W.", "orcid": "0000-0003-0241-8956" }, { "family_name": "Monson", "given_name": "Andrew", "orcid": "0000-0002-0048-2586" }, { "family_name": "Ninan", "given_name": "Joe P.", "orcid": "0000-0001-8720-5612" }, { "family_name": "Paredes", "given_name": "Leonardo A.", "orcid": "0000-0003-1324-0495" }, { "family_name": "Patel", "given_name": "Yatrik G.", "orcid": "0009-0004-7817-2547" }, { "family_name": "Robertson", "given_name": "Paul", "orcid": "0000-0003-0149-9678" }, { "family_name": "Ross", "given_name": "Gabrielle", "orcid": "0009-0006-7023-1199" }, { "family_name": "Roy", "given_name": "Arpita", "orcid": "0000-0001-8127-5775" }, { "family_name": "Schwab", "given_name": "Christian", "orcid": "0000-0002-4046-987X" }, { "family_name": "Stefansson", "given_name": "Gudmundur", "orcid": "0000-0001-7409-5688" }, { "family_name": "Stevens", "given_name": "Daniel J.", "orcid": "0000-0002-5951-8328" }, { "family_name": "Vanderburg", "given_name": "Andrew M.", "orcid": "0000-0001-7246-5438" }, { "family_name": "Wright", "given_name": "Jason", "orcid": "0000-0001-6160-5888" } ], "abstract": "We present the confirmation of TOI-5573 b, a Saturn-sized exoplanet on an 8.79 days orbit around an early M dwarf (3790 K, 0.59 R\u2299, 0.61 M\u2299, 12.30 Jmag). TOI-5573 b has a mass of 112\u207a¹\u2078\u208b\u2081\u2089 M⊕(0.35 ± 0.06 MJup) and a radius of 9.75 ± 0.47 R⊕(0.87 ± 0.04 RJup), resulting in a density of 0.66^+(0.16)_(-0.13) g cm−3, akin to that of Saturn. The planet was initially discovered by the Transiting Exoplanet Survey Satellite (TESS) and confirmed using a combination of 11 transits from four TESS Sectors (20, 21, 47, and 74), ground-based photometry from the Red Buttes Observatory, and high-precision radial velocity data from the Habitable-zone Planet Finder and NN-EXPLORE Exoplanet Investigations with Doppler spectrographs, achieving a 5σ precision on the planet’s mass. TOI-5573 b is one of the coolest Saturn-like exoplanets discovered around an M-dwarf, with an equilibrium temperature of only 528 ± 10 K, making it a valuable target for atmospheric characterization. Saturn-like exoplanets around M dwarfs likely form through core accretion, with increased disk opacity slowing gas accretion and limiting their mass. The host star’s supersolar metallicity supports core accretion, but uncertainties in M-dwarf metallicity estimates complicate definitive conclusions. Compared to other GEMS (Giant Exoplanets around M-dwarf Stars) orbiting metal-rich stars, TOI-5573 b aligns with the observed pattern that giant planets preferentially form around M-dwarfs with supersolar metallicity. Further high-resolution spectroscopic observations are needed to explore the role of stellar metallicity in shaping the formation and properties of giant exoplanets like TOI-5573 b.
", "doi": "10.3847/1538-3881/addc51", "issn": "0004-6256", "publisher": "American Astronomical Society", "publication": "Astronomical Journal", "publication_date": "2025-07", "series_number": "1", "volume": "170", "issue": "1", "pages": "55" }, { "id": "authors:r147a-pz315", "collection": "authors", "collection_id": "r147a-pz315", "cite_using_url": "https://authors.library.caltech.edu/records/r147a-pz315", "type": "article", "title": "Searching for GEMS: Discovery and Characterization of Two Brown Dwarfs Around M Dwarfs", "author": [ { "family_name": "Larsen", "given_name": "Alexander", "orcid": "0000-0002-2401-8411" }, { "family_name": "Swaby", "given_name": "Tera N.", "orcid": "0000-0002-5817-202X" }, { "family_name": "Kobulnicky", "given_name": "Henry A.", "orcid": "0000-0002-4475-4176" }, { "family_name": "Ca\u00f1as", "given_name": "Caleb I.", "orcid": "0000-0003-4835-0619" }, { "family_name": "Kanodia", "given_name": "Shubham", "orcid": "0000-0001-8401-4300" }, { "family_name": "Libby-Roberts", "given_name": "Jessica", "orcid": "0000-0002-2990-7613" }, { "family_name": "Monson", "given_name": "Andrew", "orcid": "0000-0002-0048-2586" }, { "family_name": "Gupta", "given_name": "Arvind F.", "orcid": "0000-0002-5463-9980" }, { "family_name": "Cochran", "given_name": "William", "orcid": "0000-0001-9662-3496" }, { "family_name": "Mahadevan", "given_name": "Suvrath", "orcid": "0000-0001-9596-7983" }, { "family_name": "Bender", "given_name": "Chad", "orcid": "0000-0003-4384-7220" }, { "family_name": "Diddams", "given_name": "Scott A.", "orcid": "0000-0002-2144-0764" }, { "family_name": "Halverson", "given_name": "Samuel", "orcid": "0000-0003-1312-9391", "clpid": "Halverson-Samuel" }, { "family_name": "Lin", "given_name": "Andrea S. J.", "orcid": "0000-0002-9082-6337", "clpid": "Lin-Andrea-S-J" }, { "family_name": "Moe", "given_name": "Maxwell", "orcid": "0000-0002-0870-6388" }, { "family_name": "Ninan", "given_name": "Joe", "orcid": "0000-0001-8720-5612" }, { "family_name": "Robertson", "given_name": "Paul", "orcid": "0000-0003-0149-9678" }, { "family_name": "Roy", "given_name": "Arpita", "orcid": "0000-0001-8127-5775" }, { "family_name": "Schwab", "given_name": "Christian", "orcid": "0000-0002-4046-987X" }, { "family_name": "Stefansson", "given_name": "Gudmundur", "orcid": "0000-0001-7409-5688" } ], "abstract": "Brown dwarfs bridge the gap between stars and planets, providing valuable insight into both planetary and stellar-formation mechanisms. Yet the census of transiting brown-dwarf companions, in particular around M-dwarf stars, remains incomplete. We report the discovery of two transiting brown dwarfs around low-mass hosts using a combination of space- and ground-based photometry along with near-infrared radial velocities. We characterize TOI-5389Ab (68.0_(−2.2)^(+2.2)MJ) and TOI-5610b (40.4_(−1.0)^(+1.0)MJ), two moderately massive brown dwarfs orbiting early M-dwarf hosts (Teff = 3569 ± 59 K and 3618 ± 59 K, respectively). For TOI-5389Ab, the best fitting parameters are period P = 10.40046 ± 0.00002 days, radius RBD=0.824_(−0.031)^(+0.033) RJ, and low eccentricity e=0.0962_(−0.0046)^(+0.0027). In particular, this constitutes one of the most extreme substellar-stellar companion-to-host mass ratios of q = 0.150. For TOI-5610b, the best-fitting parameters are period P = 7.95346 ± 0.00002 days, radius RBD=0.887_(−0.031)^(+0.031) RJ, and moderate eccentricity e=0.354_(−0.012)^(+0.011). Both targets are expected to have shallow, but potentially observable, occultations: \u2272500 ppm in the Johnson K band. A statistical analysis of M-dwarf/BD systems reveals for the first time that those at short orbital periods (P < 13 days) exhibit a dearth of 13 MJ < MBD < 40 MJ companions (q < 0.1) compared to those at slightly wider separations.
", "doi": "10.3847/1538-3881/adbb54", "issn": "0004-6256", "publisher": "American Astronomical Society", "publication": "Astronomical Journal", "publication_date": "2025-05", "series_number": "5", "volume": "169", "issue": "5", "pages": "246" }, { "id": "authors:chaz4-m9f06", "collection": "authors", "collection_id": "chaz4-m9f06", "cite_using_url": "https://authors.library.caltech.edu/records/chaz4-m9f06", "type": "article", "title": "NEIDSpecMatch: Stellar Parameter Estimation with NEID Spectra Using an Empirical Library", "author": [ { "family_name": "Han", "given_name": "Te", "orcid": "0000-0002-7127-7643" }, { "family_name": "Robertson", "given_name": "Paul", "orcid": "0000-0003-0149-9678" }, { "family_name": "Ca\u00f1as", "given_name": "Caleb I.", "orcid": "0000-0003-4835-0619" }, { "family_name": "Stefansson", "given_name": "Gudmundur", "orcid": "0000-0001-7409-5688" }, { "family_name": "Kanodia", "given_name": "Shubham", "orcid": "0000-0001-8401-4300" }, { "family_name": "Ninan", "given_name": "Joe P.", "orcid": "0000-0001-8720-5612" }, { "family_name": "Alvarado-Montes", "given_name": "Jaime A.", "orcid": "0000-0003-0353-9741" }, { "family_name": "Bender", "given_name": "Chad F.", "orcid": "0000-0003-4384-7220" }, { "family_name": "Dong", "given_name": "Jiayin", "orcid": "0000-0002-3610-6953" }, { "family_name": "Fernandes", "given_name": "Rachel", "orcid": "0000-0002-3853-7327" }, { "family_name": "Gupta", "given_name": "Arvind F.", "orcid": "0000-0002-5463-9980" }, { "family_name": "Halverson", "given_name": "Samuel", "orcid": "0000-0003-1312-9391", "clpid": "Halverson-Samuel" }, { "family_name": "Krolikowski", "given_name": "Daniel M.", "orcid": "0000-0001-9626-0613" }, { "family_name": "Lin", "given_name": "Andrea S. J.", "orcid": "0000-0002-9082-6337", "clpid": "Lin-Andrea-S-J" }, { "family_name": "Mahadevan", "given_name": "Suvrath", "orcid": "0000-0001-9596-7983" }, { "family_name": "Paredes", "given_name": "Leonardo A.", "orcid": "0000-0003-1324-0495" }, { "family_name": "Roy", "given_name": "Arpita", "orcid": "0000-0001-8127-5775" }, { "family_name": "Schwab", "given_name": "Christian", "orcid": "0000-0002-4046-987X" }, { "family_name": "Terrien", "given_name": "Ryan C.", "orcid": "0000-0002-4788-8858" } ], "abstract": "We introduce NEIDSpecMatch, a tool developed to extract stellar parameters from spectra obtained with the NEID spectrograph. NEIDSpecMatch is based on SpecMatch-Emp and HPFSpecMatch, which estimate stellar parameters by comparing the observed spectrum to well-characterized library spectra. This approach has proven effective for M dwarfs. Utilizing a library of 78 stellar spectra covering effective temperatures from 3000–6000 K, NEIDSpecMatch derives key parameters, including effective temperature, metallicity, surface gravity, and projected rotational velocity. Cross-validation shows median uncertainties of σ_(Teff) = 115K, σ[Fe/H] = 0.143, and σ_(logg) = 0.073 across 49 orders. We showcase its application by fitting the spectrum of an M-dwarf and discuss its utility across a wide range of spectra observed with NEID. NEIDSpecMatch is pip-installable.
", "doi": "10.3847/2515-5172/adc264", "issn": "2515-5172", "publisher": "American Astronomical Society", "publication": "Research Notes of the AAS", "publication_date": "2025-03", "series_number": "3", "volume": "9", "issue": "3", "pages": "63" }, { "id": "authors:5mk53-bb966", "collection": "authors", "collection_id": "5mk53-bb966", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220322-741611000", "type": "article", "title": "Observing the Sun as a Star: Design and Early Results from the NEID Solar Feed", "author": [ { "family_name": "Lin", "given_name": "Andrea S. J.", "orcid": "0000-0002-9082-6337", "clpid": "Lin-Andrea-S-J" }, { "family_name": "Monson", "given_name": "Andrew", "orcid": "0000-0002-0048-2586" }, { "family_name": "Mahadevan", "given_name": "Suvrath", "orcid": "0000-0001-9596-7983" }, { "family_name": "Ninan", "given_name": "Joe P.", "orcid": "0000-0001-8720-5612" }, { "family_name": "Halverson", "given_name": "Samuel", "orcid": "0000-0003-1312-9391", "clpid": "Halverson-Samuel-P" }, { "family_name": "Nitroy", "given_name": "Colin", "orcid": "0000-0001-5747-5064" }, { "family_name": "Bender", "given_name": "Chad F.", "orcid": "0000-0003-4384-7220" }, { "family_name": "Logsdon", "given_name": "Sarah E.", "orcid": "0000-0002-9632-9382" }, { "family_name": "Kanodia", "given_name": "Shubham", "orcid": "0000-0001-8401-4300" }, { "family_name": "Terrien", "given_name": "Ryan C.", "orcid": "0000-0002-4788-8858" }, { "family_name": "Roy", "given_name": "Arpita", "orcid": "0000-0001-8127-5775" }, { "family_name": "Luhn", "given_name": "Jacob K.", "orcid": "0000-0002-4927-9925" }, { "family_name": "Gupta", "given_name": "Arvind F.", "orcid": "0000-0002-5463-9980" }, { "family_name": "Ford", "given_name": "Eric B.", "orcid": "0000-0001-6545-639X" }, { "family_name": "Hearty", "given_name": "Fred", "orcid": "0000-0002-1664-3102" }, { "family_name": "Laher", "given_name": "Russ R.", "orcid": "0000-0003-2451-5482", "clpid": "Laher-Russ-R" }, { "family_name": "Hunting", "given_name": "Emily" }, { "family_name": "McBride", "given_name": "William R." }, { "family_name": "Salazar Rivera", "given_name": "Noah Isaac", "orcid": "0000-0002-0289-3135" }, { "family_name": "Rajagopal", "given_name": "Jayadev", "orcid": "0000-0002-2488-7123" }, { "family_name": "Wolf", "given_name": "Marsha J.", "orcid": "0000-0002-7827-6184" }, { "family_name": "Robertson", "given_name": "Paul", "orcid": "0000-0003-0149-9678" }, { "family_name": "Wright", "given_name": "Jason T.", "orcid": "0000-0001-6160-5888" }, { "family_name": "Blake", "given_name": "Cullen H.", "orcid": "0000-0002-6096-1749" }, { "family_name": "Ca\u00f1as", "given_name": "Caleb I.", "orcid": "0000-0003-4835-0619" }, { "family_name": "Lubar", "given_name": "Emily", "orcid": "0000-0003-0790-7492" }, { "family_name": "McElwain", "given_name": "Michael W.", "orcid": "0000-0003-0241-8956" }, { "family_name": "Ramsey", "given_name": "Lawrence W.", "orcid": "0000-0002-4289-7958" }, { "family_name": "Schwab", "given_name": "Christian", "orcid": "0000-0002-0091-7105" }, { "family_name": "Stefansson", "given_name": "Gudmundur", "orcid": "0000-0001-7409-5688" } ], "abstract": "Efforts with extreme-precision radial velocity (EPRV) instruments to detect small-amplitude planets are largely limited, on many timescales, by the effects of stellar variability and instrumental systematics. One avenue for investigating these effects is the use of small solar telescopes which direct disk-integrated sunlight to these EPRV instruments, observing the Sun at high cadence over months or years. We have designed and built a solar feed system to carry out \"Sun-as-a-star\" observations with NEID, a very high precision Doppler spectrometer recently commissioned at the WIYN 3.5 m Telescope at Kitt Peak National Observatory. The NEID solar feed has been taking observations nearly every day since 2020 December; data is publicly available at the NASA Exoplanet Science Institute NEID Solar Archive: https://neid.ipac.caltech.edu/search_solar.php. In this paper, we present the design of the NEID solar feed and explanations behind our design intent. We also present early radial velocity (RV) results which demonstrate NEID's RV stability on the Sun over 4 months of commissioning: 0.66 m s\u207b\u00b9 rms under good sky conditions and improving to 0.41 m s\u207b\u00b9 rms under best conditions.", "doi": "10.3847/1538-3881/ac5622", "issn": "0004-6256", "publisher": "American Astronomical Society", "publication": "Astronomical Journal", "publication_date": "2022-04", "series_number": "4", "volume": "163", "issue": "4", "pages": "Art. No. 184" }, { "id": "authors:ec9k3-0kk81", "collection": "authors", "collection_id": "ec9k3-0kk81", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210112-102626828", "type": "book_section", "title": "The NEID spectrometer: fibre injection system design", "book_title": "Ground-based and Airborne Instrumentation for Astronomy VIII", "author": [ { "family_name": "Schwab", "given_name": "Christian", "orcid": "0000-0002-4046-987X", "clpid": "Schwab-Christian" }, { "family_name": "Monson", "given_name": "Andrew J.", "orcid": "0000-0002-0048-2586", "clpid": "Monson-Andrew-J" }, { "family_name": "Kanodia", "given_name": "Shubham", "orcid": "0000-0001-8401-4300", "clpid": "Kanodia-Shubham" }, { "family_name": "Lubar", "given_name": "Emily", "orcid": "0000-0003-0790-7492", "clpid": "Lubar-Emily" }, { "family_name": "Lin", "given_name": "Andrea S. J.", "orcid": "0000-0002-9082-6337", "clpid": "Lin-Andrea-S-J" }, { "family_name": "Nitroy", "given_name": "Colin", "clpid": "Nitroy-Colin" }, { "family_name": "Halverson", "given_name": "Samuel", "orcid": "0000-0003-1312-9391", "clpid": "Halverson-Samuel-P" }, { "family_name": "Gong", "given_name": "Qian", "clpid": "Gong-Qian" }, { "family_name": "Terrien", "given_name": "Ryan C.", "orcid": "0000-0002-4788-8858", "clpid": "Terrien-Ryan-C" }, { "family_name": "Ninan", "given_name": "Joe P.", "orcid": "0000-0001-8720-5612", "clpid": "Ninan-Joe-P" }, { "family_name": "Bender", "given_name": "Chad", "orcid": "0000-0003-4384-7220", "clpid": "Bender-Chad-F" }, { "family_name": "Blake", "given_name": "Cullen", "orcid": "0000-0002-6096-1749", "clpid": "Blake-Cullen-H" }, { "family_name": "Hearty", "given_name": "Frederick R.", "clpid": "Hearty-Frederick-R" }, { "family_name": "Mahadevan", "given_name": "Suvrath", "orcid": "0000-0001-9596-7983", "clpid": "Mahadevan-Suvrath" }, { "family_name": "McElwain", "given_name": "Michael W.", "orcid": "0000-0003-0241-8956", "clpid": "McElwain-Michael-W" }, { "family_name": "Robertson", "given_name": "Paul M.", "clpid": "Robertson-Paul-M" }, { "family_name": "Roy", "given_name": "Arpita", "orcid": "0000-0001-8127-5775", "clpid": "Roy-Arpita" }, { "family_name": "Stef\u00e1nsson", "given_name": "Gu\u00f0mundur", "clpid": "Stef\u00e1nsson-Gu\u00f0mundur-K" } ], "contributor": [ { "family_name": "Evans", "given_name": "Christopher J.", "clpid": "Evans-Christopher-J" }, { "family_name": "Bryant", "given_name": "Julia J.", "clpid": "Bryant-Julia-J" }, { "family_name": "Motohara", "given_name": "Kentaro", "clpid": "Motohara-Kentaro" } ], "abstract": "NEID is a high resolution echelle spectrograph designed to enable extremely precise Doppler radial velocity observations of stars in the 380-930nm wavelength range1. It has recently been installed at the 3.5m WIYN telescope at Kitt Peak National Observatory, and is currently being commissioned. The design is based on a white pupil layout with a monolithic parabolic primary mirror and a 195mm pupil size on the R4 Echelle grating. Here we describe the optical and mechanical design, assembly, and alignment of the fiber injection system which converts the native focal ratio of the sky, calibration, and science fibers to the focal ratio required to form the 195mm collimated beam.", "doi": "10.1117/12.2563248", "isbn": "9781510636811", "publisher": "Society of Photo-Optical Instrumentation Engineers (SPIE)", "place_of_publication": "Bellingham, WA", "publication_date": "2020-12-13", "pages": "Art. No. 114474L" }, { "id": "authors:7eqet-7ef38", "collection": "authors", "collection_id": "7eqet-7ef38", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210120-145942312", "type": "book_section", "title": "A solar feed for NEID", "book_title": "Ground-based and Airborne Instrumentation for Astronomy VIII", "author": [ { "family_name": "Lin", "given_name": "Andrea", "orcid": "0000-0002-9082-6337", "clpid": "Lin-Andrea-S-J" }, { "family_name": "Bender", "given_name": "Chad F.", "orcid": "0000-0003-4384-7220", "clpid": "Bender-Chad-F" }, { "family_name": "Ford", "given_name": "Eric", "clpid": "Ford-Eric" }, { "family_name": "Guo", "given_name": "Zhao", "orcid": "0000-0002-0951-2171", "clpid": "Guo-Zhao" }, { "family_name": "Halverson", "given_name": "Samuel", "orcid": "0000-0003-1312-9391", "clpid": "Halverson-Samuel-P" }, { "family_name": "Hearty", "given_name": "Fred", "orcid": "0000-0002-1664-3102", "clpid": "Hearty-Frederick-R" }, { "family_name": "Hunting", "given_name": "Emily", "clpid": "Hunting-Emily" }, { "family_name": "Kanodia", "given_name": "Shubham", "orcid": "0000-0001-8401-4300", "clpid": "Kanodia-Shubham" }, { "family_name": "Kaplan", "given_name": "Kyle", "orcid": "0000-0001-6909-3856", "clpid": "Kaplan-Kyle-F" }, { "family_name": "Mahadevan", "given_name": "Suvrath", "orcid": "0000-0001-9596-7983", "clpid": "Mahadevan-Suvrath" }, { "family_name": "McElwain", "given_name": "Michael W.", "orcid": "0000-0003-0241-8956", "clpid": "McElwain-Michael-W" }, { "family_name": "Monson", "given_name": "Andrew", "orcid": "0000-0002-0048-2586", "clpid": "Monson-Andrew-J" }, { "family_name": "Ninan", "given_name": "Joe", "orcid": "0000-0001-8720-5612", "clpid": "Ninan-Joe-P" }, { "family_name": "Nitroy", "given_name": "Colin", "orcid": "0000-0001-5747-5064", "clpid": "Nitroy-Colin" }, { "family_name": "Rajagopal", "given_name": "Jayadev", "clpid": "Rajagopal-Jayadev-K" }, { "family_name": "Ramsey", "given_name": "Lawrence", "orcid": "0000-0002-4289-7958", "clpid": "Ramsey-Lawrence-W" }, { "family_name": "Robertson", "given_name": "Paul", "orcid": "0000-0003-0149-9678", "clpid": "Robertson-Paul-M" }, { "family_name": "Roy", "given_name": "Arpita", "orcid": "0000-0001-8127-5775", "clpid": "Roy-Arpita" }, { "family_name": "Schwab", "given_name": "Christian", "orcid": "0000-0002-4046-987X", "clpid": "Schwab-Christian" }, { "family_name": "Stefansson", "given_name": "Gudmundur", "orcid": "0000-0001-7409-5688", "clpid": "Stefansson-Gudmundur-K" }, { "family_name": "Stevens", "given_name": "Daniel J.", "orcid": "0000-0002-5951-8328", "clpid": "Stevens-Daniel-J" }, { "family_name": "Terrien", "given_name": "Ryan", "orcid": "0000-0002-4788-8858", "clpid": "Terrien-Ryan-C" }, { "family_name": "Wright", "given_name": "Jason", "orcid": "0000-0001-6160-5888", "clpid": "Wright-Jason-T" } ], "contributor": [ { "family_name": "Evans", "given_name": "Christopher J.", "clpid": "Evans-Christopher-J" }, { "family_name": "Bryant", "given_name": "Julia J.", "clpid": "Bryant-Julia-J" }, { "family_name": "Motohara", "given_name": "Kentaro", "clpid": "Motohara-Kentaro" } ], "abstract": "NEID is a radial velocity (RV) instrument including an ultra-stabilized fiber-fed spectrograph, installed in 2019 at the 3.5m WIYN telescope at Kitt Peak National Observatory. Accompanying it is a solar feed system built to supply the spectrograph with disk-integrated sunlight. Observing the Sun \"as a star\" is essential for developing and validating mitigation strategies for RV variations due to stellar activity and instrument systematics, thus enabling more-effective detections of lower-mass exoplanets. In this paper, we will detail the design of the NEID solar feed system and showcase early results addressing NEID systematics and solar RV variability.", "doi": "10.1117/12.2561520", "isbn": "9781510636811", "publisher": "Society of Photo-Optical Instrumentation Engineers", "place_of_publication": "Bellingham, WA", "publication_date": "2020-12-13", "pages": "Art. No. 114473L" }, { "id": "authors:ztwvb-v3z82", "collection": "authors", "collection_id": "ztwvb-v3z82", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201113-100153002", "type": "article", "title": "A Mini-Neptune and a Radius Valley Planet Orbiting the Nearby M2 Dwarf TOI-1266 in Its Venus Zone: Validation with the Habitable-zone Planet Finder", "author": [ { "family_name": "Stef\u00e1nsson", "given_name": "Gu\u00f0mundur", "orcid": "0000-0001-7409-5688", "clpid": "Stef\u00e1nsson-Gu\u00f0mundur" }, { "family_name": "Kopparapu", "given_name": "Ravi", "orcid": "0000-0002-5893-2471", "clpid": "Kopparapu-Ravi-kumar" }, { "family_name": "Lin", "given_name": "Andrea", "orcid": "0000-0002-9082-6337", "clpid": "Lin-Andrea-S-J" }, { "family_name": "Mahadevan", "given_name": "Suvrath", "orcid": "0000-0001-9596-7983", "clpid": "Mahadevan-Suvrath" }, { "family_name": "Ca\u00f1as", "given_name": "Caleb I.", "orcid": "0000-0003-4835-0619", "clpid": "Ca\u00f1as-C-I" }, { "family_name": "Kanodia", "given_name": "Shubham", "orcid": "0000-0001-8401-4300", "clpid": "Kanodia-Shubham" }, { "family_name": "Ninan", "given_name": "Joe P.", "orcid": "0000-0001-8720-5612", "clpid": "Ninan-J-P" }, { "family_name": "Cochran", "given_name": "William D.", "orcid": "0000-0001-9662-3496", "clpid": "Cochran-W-D" }, { "family_name": "Endl", "given_name": "Michael", "orcid": "0000-0002-7714-6310", "clpid": "Endl-M" }, { "family_name": "Hebb", "given_name": "Leslie", "orcid": "0000-0003-1263-8637", "clpid": "Hebb-L" }, { "family_name": "Wisniewski", "given_name": "John", "orcid": "0000-0001-9209-1808", "clpid": "Wisniewski-J-P" }, { "family_name": "Gupta", "given_name": "Arvind", "orcid": "0000-0002-5463-9980", "clpid": "Gupta-Arvind-F" }, { "family_name": "Everett", "given_name": "Mark", "orcid": "0000-0002-0885-7215", "clpid": "Everett-M-E" }, { "family_name": "Bender", "given_name": "Chad F.", "orcid": "0000-0003-4384-7220", "clpid": "Bender-Chad-F" }, { "family_name": "Diddams", "given_name": "Scott A.", "orcid": "0000-0002-2144-0764", "clpid": "Diddams-S-A" }, { "family_name": "Ford", "given_name": "Eric B.", "orcid": "0000-0001-6545-639X", "clpid": "Ford-E-B" }, { "family_name": "Fredrick", "given_name": "Connor", "orcid": "0000-0002-0560-1433", "clpid": "Fredrick-Connor" }, { "family_name": "Halverson", "given_name": "Samuel", "orcid": "0000-0003-1312-9391", "clpid": "Halverson-S-P" }, { "family_name": "Hearty", "given_name": "Fred", "orcid": "0000-0002-1664-3102", "clpid": "Hearty-Fred-R" }, { "family_name": "Levi", "given_name": "Eric", "clpid": "Levi-Eric" }, { "family_name": "Maney", "given_name": "Marissa", "orcid": "0000-0001-8222-9586", "clpid": "Maney-Marissa" }, { "family_name": "Metcalf", "given_name": "Andrew J.", "orcid": "0000-0001-5000-1018", "clpid": "Metcalf-A-J" }, { "family_name": "Monson", "given_name": "Andrew", "orcid": "0000-0002-0048-2586", "clpid": "Monson-A-J" }, { "family_name": "Ramsey", "given_name": "Lawrence W.", "orcid": "0000-0002-4289-7958", "clpid": "Ramsey-L-W" }, { "family_name": "Robertson", "given_name": "Paul", "orcid": "0000-0003-0149-9678", "clpid": "Robertson-P" }, { "family_name": "Roy", "given_name": "Arpita", "orcid": "0000-0001-8127-5775", "clpid": "Roy-Arpita" }, { "family_name": "Schwab", "given_name": "Christian", "orcid": "0000-0002-0091-7105", "clpid": "Schwab-C" }, { "family_name": "Terrien", "given_name": "Ryan C.", "orcid": "0000-0002-4788-8858", "clpid": "Terrien-R-C" }, { "family_name": "Wright", "given_name": "Jason T.", "orcid": "0000-0001-6160-5888", "clpid": "Wright-J-T" } ], "abstract": "We report on the validation of two planets orbiting the nearby (36 pc) M2 dwarf TOI-1266 observed by the TESS mission. This system is one of a few M dwarf multiplanet systems with close-in planets where the inner planet is substantially larger than the outer planet. The inner planet is sub-Neptune-sized (R = 2.46 \u00b1 0.08 R_\u2295) with an orbital period of 10.9 days, while the outer planet has a radius of 1.67_(-0.11)^(+0.09) R_\u2295 and resides in the exoplanet radius valley\u2014the transition region between rocky and gaseous planets. With an orbital period of 18.8 days, the outer planet receives an insolation flux of 2.4 times that of Earth, similar to the insolation of Venus. Using precision near-infrared radial velocities with the Habitable-zone Planet Finder Spectrograph, we place upper mass limits of 15.9 and 6.4 M_\u2295 at 95% confidence for the inner and outer planet, respectively. A more precise mass constraint of both planets, achievable with current radial velocity instruments given the host star brightness (V = 12.9, J = 9.7), will yield further insights into the dominant processes sculpting the exoplanet radius valley.", "doi": "10.3847/1538-3881/abbe19", "issn": "1538-3881", "publisher": "American Astronomical Society", "publication": "Astronomical Journal", "publication_date": "2020-12", "series_number": "6", "volume": "160", "issue": "6", "pages": "Art. No. 259" } ]